As is known in the art, electric switching devices installed in low voltage electric circuits (that is to say, for applications with nominal voltages up to 1000 VAC/1500 VDC), for example, circuit breakers, disconnectors, and contactors, which are referred to as “switching devices”, can be devices devised to allow the correct operation of specific parts of the electric circuit where they can be installed and of the loads operatively connected thereto.
The switching devices include one or more poles each having a movable contact which can be coupled/decoupled to/from a respective fixed contact. A suitable operating mechanism is configured to operate on the movable contacts to cause the movement thereof from a coupled position with the respective fixed contacts to a separated position with respect to the fixed contacts, and vice-versa.
In accordance with the position assumed by the movable contacts of the poles and the respective operating mechanism, the switching device can assume a closed state (movable contacts are in the coupled position), an open state (movable contacts are in the separated position), or a tripped state (operating mechanism tripped but the movable contacts are in the coupled position).
In general, switching devices include a protection device, for example, an electronic device or protection relay, capable of: detecting (by means of suitable sensors) the operating conditions of the electric circuit where the respective switching device is installed; and in case of faults or overloads, driving the opening of the switching device by acting on the operating mechanism.
In addition to the driving and control functions, the protection device is capable of acquiring and making available the information related to the operating conditions of the electric circuit where the switching device is installed.
In known solutions, the switching device includes an internal communication bus which is operatively connected to the protection device so as to make a communication channel available between the electronic protection device and one or more accessory electronic devices.
Among the accessory devices utilized, there are foreseen communication modules capable of placing in communication, that is to say interfacing, the internal bus (and hence the electronic protection device) to a communication bus external to the switching device, even when the communication protocol implemented in the external communication bus is different from the communication protocol implemented in the internal communication bus.
For example, a communication network in an electric circuit can include a first communication bus, or system bus, and a second communication bus, or panel bus, which are operationally connected to a first communication module and a second communication module of a switching device installed in the electric circuit. The first communication module and the second communication module establish the communication interface between the system bus and the panel bus, on one side, and the internal bus of the switching devices in the electric circuit, on the other side.
Although the described solutions can already implement an efficient communication system available to the electronic protection device, there is still room for expanding the functionality and versatility of the communication modules employed, so as to further exploit and improve the communication capabilities already available to the electronic protection device.